Indicia rolling attachment in screw machines



P 1965 E. w. BRINKMAN ETAL 3,205,813

INDICIA ROLLING ATTACHMENT IN SCREW MACHINES Filed Dec. 27, 1962 3 Sheets-Sheet 1 INVENTORS EARL W. BRINKMAN AND ROBERT A. LEE

E. \N. BRINKMAN ETAL INDICIA ROLLING ATTACHMENT IN SCREW MACHINES 3 Sheets-Sheet 2 Sept. 14, 1965 Filed Dec. 27. 1962 III 5| s3 22 25 g; '28 22 29 25 25 2s v 28 i i 5 q FIG. 4

INVENTORS EARL W. BRINKMAN AND ROERT A. LEE

p 14, 1965 E. w. BRINKMAN ETAL 3,205,813

INDICIA ROLLING ATTACHMENT IN SCREW MACHINES Filed Dec. 27, 1962 3 Sheets-Sheet 3 INVENTORS EARL W. BRINKMAN AND ROBERT A. LEE

W qfibrruzy United States Patent 3,205,813 INDICIA ROLLING ATTACHMENT 1N SCREW MACHllNES Earl W. Brinlkman and Robert A. Lee, Rochester, N.Y.,

assignors to Davenport Machine Tool Company, lino,

Rochester, N.Y., a corporation of New York Filed Dec. 27, 1962, Ser. No. 247,696 13 Claims. (Cl. 101-7) This invention relates to screw machines, and more particularly to a letter rolling attachment for use on screw machines for rolling a name or other identifying indicia onto a workpiece while it is being processed on a screw machine.

One major disadvantage of prior letter rolling attachments for screw machines has been the difliculty in getting the first letters rolled on a workpiece to the same depth as the rest of the letters. Prior letter roll holders have usually employed a spring to return the roll to its intial position after it has engraved the rotating stock. This means that the stock, upon initially engaging the letter roll, must rotate the roll from a dead stop against the tension of the return spring, making it very difiicult to get the first letters embossed on the workpiece to the same depth as the rest of the letters.

There is another lettering roll holder, which uses a spring and trigger mechanism which locks the roll after it has been rolled, but it is actually locked against spring tension. When the slide, that carries the roll holder, is returned to a given position, the roll is released to bring it back to its proper starting point. This mechanism is, however, complicated and costly. Moreover, with either of the letter roll holders described, it has been possible to do only lettering in a given position of the rotating head or work turret of the machine, and for a forming operation it has been necessary to retract the letter roll holder, and hence the lettering roll carried thereby, and to index the head or turret into another position.

The primary object of this invention is to provide an improved letter rolling attachment for screw machines, which will operate more efiiciently than prior lettering attachments.

Another object of this invention is to provide an improved letter rolling attachment which will so operate that all of the characters to be rolled onto the workpiece will be rolled to a uniform depth.

Another object of this invention is to provide a holder of the type described which is adapted also to hold a cutting or forming tool so that a cutting or forming operation may be performed on a workpiece immediately after the lettering thereof and without having to index the rotating head or turret to another position.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is a side elevational view of a letter rolling attachment made in accordance with one embodiment of this invention, in its lower, operative position, and also showing a fragment of the screw machine on which the letter roll and its holder are mounted;

FIG. 2 is a front elevational view of this letter rolling attachment and of a portion of the machine, the attachment being shown in position immediately after it has completed an operation;

FIG. 3 is a plan view of the letter roll holder and machine;

FIG. 4 is a front elevational view similar to FIG. 2 but showing the letter roll holder in inoperative position and the letter roller in its cocked position;

FIG. 5 is a fragmentary sectional view taken on the ice line 55 in FIG. 4 and looking in the direction of the arrows;

FIG. 6 is a side elevational view of a combined roll holder and forming attachment made in accordance with a further embodiment of this invention;

FIG. 7 is a sectional view taken along the line 77 in FIG. 6 and looking in the direction of the arrows, parts being broken away; and

FIG. 8 is a fragmentary front elevational view of the holder shown in FIG. 6.

Referring now to the drawings by numerals of reference, and first to the embodiment illustrated in FIGS. 1 to 5, inclusive, 11 denotes the letter roll holder, and 12 designates the frame of a conventional screw machine on which the attachment is mounted. Although a letter rolling attachment utilizing the principles of the present invention can be used on different conventional automatic screw machines or lathes, it is herein shown as applied to a Davenport automatic screw machine, of which only a fragment is illustrated. 13 designates the operating cam of the machine (shown in phantom by the broken lines in FIG. 1) which is secured to the motor driven timing shaft of the machine for rotation therewith to effect the operations of the machine in proper timed sequence. The cam operating through a suitable cam follower 14 reciprocates a connecting rod 15 that is pivotally connected at 16 to one arm of a lever 17 which is pivotally mounted intermediate its ends by means of shaft 18 on frame 12 for rotation about a horizontal axis. The other arm of the lever 17 is pivotally connected by means of a pin 19 to an eye bolt 20. The eye bolt 20 is adjustably connected by a nut 21 to the threaded shank of a further eye bolt 22 to form therewith, and with the nut, an adjustable turnbuckle.

The eye bolt 22 at the lower end of the turnbuckle is pivotally connected by means of a horizontally disposed pin 24 to a vertically reciprocable slide block 23. Pin 24 is mounted in two, laterally spaced bearing lugs 25 which are integral with and which project outwardly from the front face of the slide block 23. The slide block 23 has at its rear a dovetailed guide portion 26 by which it is guided for vertical reciprocation relative to frame 12 in a correspondingly shaped groove formed in the front face of a stationary mounting plate 27 that is carried by the frame. The slide 23 is constantly urged in a vertical direction upwardly by means of two tension springs 28, which are connected at their upper ends to a stationary bracket (not illustrated) mounted on the machine frame above the mounting plate; and which at their lower ends are connected adjacent the opposite ends, respectively,

"of a horizontally disposed pin 29 which extends through and is secured in aligned apertures in the bearing lugs 25 on the slide block 23.

Secured by a bolt 31 and a capping block 32 to the slide block 23 adjacent the lower end thereof are three, aligned, substantially rectangularly shaped plates 33, 34 and 35, which form the body of holder 11. The innermost of these three plates, the plate 33, has its rear face positioned flush against the face of the slide 23, and its front face abutting the rear face of the intermediate plate 34. The front face of plate 34 abuts the rear face of the outermost plate 35. The rear face of the capping block 32 seats against the front face of plate 35. The bolt 31 passes through aligned openings in the plates 33 to 35, and is threaded into the slide 23. Dowel pins (not illustrated) also help secure the three plates 33 to 35 to the slide.

Secured in the plate 33 adjacent its lower edge, is an annular bearing 36. A shaft 37 is rotatably mounted in this bearing and in an aligned bearing 38 housed in intermediate plate 34. The portion of shaft 37, which is journaled in bearing 38 is of slightly reduced diameter as compared with that portion which is journaled in hearing 36; and the shaft is of still further reduced diameter at its outer end where it projects into a circular opening 39 extending through the outer plate 35.

The innermost plate 33 is provided with a shallow, arcuate recess 41 (FIGS. 1 and 2), which opens at the bottom and front side of the plate 33. Housed in this recess 41, and secured by a setscrew 42 to theshaft 37 for rotation therewith is a segmental lettering roller 43. The lettering roller 43 has an arcuate portion extending coaxially about the axis of shaft 37 for approximately 135 on which the letters, and/or numerals, which are to be rolled on the workpieces, are embossed. The roller has shoulders 44 at opposite ends of its character-bearing portion which are adapted to engage a stationary pin 45 to limit the movement of the roller in opposite directions. Pin 45 extends through aligned openings in plates 33, 34 and 35.

Intermediate plate 34 has a shallow recess 46 (FIG. 1) in its front face. Secured by nuts and a washer 47 to the reduced diameter portion of the shaft 37 to rotate in the recess 46 is a pinion 48. A resilient disk 49 is snugly inserted into opening 39 to prevent dirt or metal shavings from entering the area in which pinion 48 rotates.

Secured in the intermediate plate 34, parallel. to the shaft 37, is a shaft 50 (FIG. 2). Mounted on shaft 50 in the recess 46 in the intermediate plate is a gear segment 51 whose teeth 52 (FIG. 2) mesh with the teeth of the pinion 48. Secured in the lower end of. the annular wall of a cylindrical plunger 55 to project laterally therefrom is a rigid connector pin 53. Pin 53 engages in a radial but inclined slot 54 in the segment 51, so that the segment is rotated in one direction or the other as the plunger is moved up or down.

Plunger 55 is slidably mounted in a vertical bore 56 (FIG. 2) formed in the outer plate 35. A cap 57 is threaded into and seals the upper end of the plunger 55. A coiled compression spring 58 (FIG. 2) is mounted in the plunger between the cap 57 and a stationary pin 59 which extends through diametrally opposed, vertically extending slots 66 formed in the annular wall of the plunger 55 intermediate the ends thereof. The stationary pin 59 is secured in plate 35 transversely of pin 53. The compression spring 58 tends constantly to urge the plunger 55 out of its cocked position as shown in FIG. 4 to its released or fired position as shown in FIG. 2.

Secured by a screw 62 to the face of the slide 23 so as to reciprocate vertically therewith is a block 61. The upper and lower faces of the block 61 abut, respectively, against the undersides of the lugs 25 and the upper edges of the three plates 33, 34 and 35, thereby tending further to resist any vertical shifting of the three plates when the letter roller 43 is moved into its operative position as described below.

Secured at the upper edge of the intermediate plate 34 and extending vertically upwardly therefrom is a stationary pivot pin 63 (FIGS. 3 and Mounted intermediate its ends on the pivot pin 63 to pivot thereabout in a horizontal lane is a latch 64. At its inner end the latch is provided with a tail portion 65 (FIGS. 3 and 5) which is adapted to overlie a shoulder 66 (FIGS. 2 and 5 formed on the plunger cap 57 when the plunger 55 is in its cocked position as shown in FIG. 4. Integral with and projecting vertically upwardly from the tail portion 65 of the latch is a pin 67 which is connected by a coiled tension spring 68 to a stationary pin 69 secured to and projecting upwardly from the upper edge of the plate 35. The spring 68 tends constantly to rotate the latch 64 in a clockwise direction about its pivot pin 63 as shown in FIG. 5. At its opposite or outer end, the latch 64 is provided with a cylindrical boss 70 which projects horizontally outwardly beyond one side of the intermediate plate 34. At the same side of the intermediate plate 34 a latch tripping cam 72 is adjustably mounted to the side of the mounting plate 27 by means of a right angle bracket 73 and bolts 74. The bolts 74 pass through vertically and horizontally disposed slots 75 and 76, respectively, (FIG. 1) in the bracket, so that the cam 72 may be adjusted horizontally and vertically to dispose its camming surface 77 in the path of the lug or boss 70 carried by the latch 64 when the latter is reciprocated vertically by the slide 23.

Mounted on the frame 12 above the plunger 55 is a cocking screw 83, which is positioned in alignment with the plunger. The cocking screw is secured by a nut 85 to a bracket 84, which is adjustably secured by means of screws 36 to an arm 87, that, in turn, is secured by bolts 88 to the frame of the machine.

When the follower 14 is on the low spot of cam 13, the springs 28 lift the slide 23 to its uppermost position, and the cocking pin 83 pushes the plunger downwardly on the slide against the resistance of spring 58; and the latch 64 is snapped by spring 68 over the shoulder 66 on the plunger cap 57 locking the plunger in its lower or cocked position. The movement downwardly of the plunger relative to the slide to cocking position, of course, causes the pin 53 to rotate segment 51, which, in turn, rotates lettering roller 43 to its starting position.

In operation, workpieces 80 are mounted in conventional fashion in the machine spindles, one of which is shown at 81. These rotate about axes parallel to the axis of rotation of the letter roll shaft 37. As each work spindle is indexed into lettering position, and the follower 14 rides down on the low part of the operating cam 13, the springs 28 raise the slide 23 to its uppermost position (FIG. 4). In this movement, the plunger cap 57 engages cocking screw 83; and the plunger 55 is forced downwardly to its lowermost position (FIG. 4) until the latch 64 is pivoted by the spring 68 into locking engagement with the shoulder 66 on the plunger cap 57. This movement of the plunger to its lowermost position causes, as described, the segment 51 to rotate the pinion 48 and the letter roller 43 counterclockwise. The letter roller is thus held in its extreme counterclockwise or cocked position as shown in FIG. 4 until, in its continued rotation, the arm 17 actuated by the operating cam 13 forces the slide 23 downwardly a sufficient distance so that the lug 71 on the latch 64 engages the camming surface of the cam 72. As the lug 70 rides on cam 72 the latch 64 is pivoted counterclockwise (FIG. 5) slightly about its pivotal axis until the latch slides off the shoulder 66 on the plunger cap 57, whereupon the plunger is forced vertically upwardly by the compression spring 58. The upward movement of the plunger 55 and of the connector pin 53 carried thereby, causes the segment 51 to rotate the pinion 48 and the letter roller 43 clockwise about their axes in FIGS. 2 and 4. The position of release of latch 64 is determined by trial and adjustment of nut 21 to bring the slide 23 to proper lettering depth. The cam 72 is so positioned that the disengagement of latch 64 and the upward movement of plunger 55 occur before the slide 23 has brought the lettering roller into operative relation with the workpiece and before the lettering roller itself has rotated into operative position. The lettering roller is therefore rotating as it engages the rotating stock. The slide dwells very briefly because of contour of cam 13, allowing the lettering roller to turn the first character into the workpiece. The lettering roller is then driven by the rotating workpiece through frictional engagement of their peripheral surfaces until the lettering roller reaches its extreme clockwise position as shown in FIG. 2, where one of its bearing surfaces 44 engages stop pin 45. Because it has only a segmental peripheral surface the lettering roller is now disengaged from the stock as shown in FIG. 2. When follower 14 again rides down on the operating cam 13 the rocker arm 17 pivots counterclockwise; and the springs 28 elevate the slide 23.so that the lettering roller is returned to its cocked position as described above.

It will be apparent thatthe extent to which the letters or numerals on the letter roller 43 are pressed radially inwardly into the rotating stock during the engraving of the latter, will depend upon the extent to which the slide 23 is urged downwardly by the turnbuckle before the lettering roller engages the workpiece. The turnbuckle may be adjusted to control the depth of the engraving. Screw 83 is adjusted to position cap 66 so that in operation of the apparatus latch 64 can engage over its shoulder 66. After correct lettering depth is obtained, adjustment for release of plunger 55 is made by adjustment of cam 72 on mounting plate 27.

Referring now to the modified holder 111 illustrated in FIGS. 6 to 8, wherein the same numerals are employed to identify parts identical to those employed in the first embodiment, a relatively simple modification of the holder 11 embodied in the FIGS. 1 to 5 permits a further operation to be performed on the rotating stock immediately after the engraving thereof by the letter roller. This modified form of holder employs a slightly difierent slide 123 which is mounted for a vertical reciprocation on a mounting block 27. This slide has lugs 125 that are connected to an operating cam 113 (broken lines in FIG. 6) by means of a turnbuckle 95 cooperating with members similar to those identified by the numerals 15 to 22 in the first described embodiment of the invention. Slide 123 differs from the slide 23 primarily in that at its lower end slide 123 is provided with a substantially semi-circular recess 102 (FIGS. 6 and 7) in which a tool mounting plate 103 of generally semi-circular configuration is secured by means of three bolts 104 which thread into the slide. Plate 103 has an integral hub portion 105 which projects outwardly from the recess 102 in plate 123 and upon which there is seated at segmental tool-adjusting plate 106. The adjusting plate 106 is provided on its periphery with spur gear teeth 107.

Integral with the hub portion of mounting plate 103 and projecting outwardly beyond and slightly offset downwardly from hub portion 105 is a centering portion 108 (FIGS. 6 and 7). The portion 108 projects coaxially into the bore of a conventional, stationary, annular forming tool 109. Forming tool 109 is connected to adjusting plate 106 by means of a dowel pin 111 which extends from a hole in tool 109 into an axially aligned hole (FIG. 6) in the adjusting plate 106. A conventional adjusting tool of the type having teeth adapted to mesh with teeth 107 on plate 106, may be employed in a conventional manner to adjust tool 109 axially about its axial centerline.

Also extending into the bore of tool 109 at the end thereof opposite portion 108 is a letter roll shaft 137 somewhat similar to that employed in the embodiment illustrated in FIGS. 1 to 5. Surrounding shaft 137 and abutting the front face of tool 109 is a relatively thin spacer plate 112. From the bore of tool 109 shaft 137 extends axially outwardly beyond spacer plate 112 and through axially aligned openings in three aligned, holder plates 33, 34- and 35, respectively, which are substantially identical to those described in the first embodiment. The plates 33, 34 and 35 are secured to the slide 123 to reciprocate therewith by means of an inverted substantially U shaped capping plate 132, and bolt 131 which passes through plates 132, 33, 34 and 35 and threads into the face of block 123 in much the same manner as in the first embodiment.

A segmental, disc-shaped printing or letter roller 143 is secured to shaft 137 to oscillate in an arcuate recess formed in the outer face of plate 33. Unlike the letter roller 43 of the first embodiment, the embossed, arcuate portion of letter roller 143 extends coaxially about the centerline of shaft 137 for approximately only 90 degrees rather than 135 degrees. Thus, as will be more apparent from a comparison of FIGS. 2 and 5 with FIG. 8, the letter roller 143, when in either one of its two extreme positions, will not extend below the lower edges of the 0 aligned plates 133 to 135. A pin 145 is secured in aligned openings in spacer plate 112 and plate 33, and projects into the recess in which roller 14-3 is mounted thereby to limit rotation of the roller in a manner similar to that of pin 45 in the first embodiment.

Secured to shaft 137 to oscillate in a recess in plate 34 is a pinion 4.8 which is driven in response to the oscillation of a segmental gear (not illustrated) and reciprocating plunger 55 substantially identical to the segmental gear 51 and plunger 55, respectively, described in the first embodiment.

Since the mechanism for oscillating the letter roll 143 is substantially identical to that illustrated in FIGS. 1 to 5, further description thereof is thought to be unnecessary. However, in this second embodiment, the spacing block 61 employed in the first embodiment is eliminated, and a clamp screw 114 is threaded at one end into slide 123 and seats at its opposite end in a recess formed-in the inner face of the clamping cover 132 thereby to prevent any undesirable angular shifting of the latter about screw 131.

For operating the second embodiment, the operating cam 113 is provided with a first camming surface 171 (FIG. 6) which is designed first to advance slide 123 toward the rotating workpiece held in the spindle 181 (FIG. 6) until the latch 64 is tripped by cam 72 thereby to release the plunger 55, producing oscillation of the letter roller 143. At this point the slide 123 dwells long enough to permit letter roller 143 to be rotated clockwise (FIGS. 7 and 8) in engagement with the stock 180 until the roller has cleared the workpiece as shown by the broken lines in FIG. 8. Having thus engraved the stock 180, a second camming surface 172 on the operating cam 113 then again advances slide 123 until the cutting edge of the stationary tool 109 carried by slide 123 engages stock 180 as shown in FIG. 6. Tool 109 then cuts a circumferential groove (FIGS. 6 and 7) in the rotating stock 180 rea-rwardly of the engraved end of the stock, and to a depth depending upon the extent to which slide 123 is advanced by the camming surface 172. After the tool 109 has formed the required surface on the rotating workpiece 180 the operating earn 113 permits slide 123 to be retracted by the springs 28 until the cocking pin 83 engages plunger 55 and causes the letter roller 143 to be rotated counterclockwise in FIG. 8 back to its cocked position so that the engraving cycle may be repeated when the slide is once again advanced toward a piece of rotating stock.

From the foregoing it will be apparent that applicants letter ro-ll holder serves to substantially improve the quality of engraving or printing as compared with prior printing or letter roll holding devices. By imparting rotary motion to the letter roll just prior to its engagement with the rotating workpiece, applicants deV-ice assures that the letters or numerals engraved upon the workpiece will all be impressed into the surface of the stock for substantially equal radial depths thereby providing a more legible marking of the stock. Moreover, with applicants improved holder it is possible .to perform both the engraving and the forming operations on a piece of stock successively without having to return the holder to an inoperative or letter roll cocking position between performance of the two operations. Furthermore, not only is applicants device relatively easy to assemble and disassemble, but it is possible in the case of the second embodiment to adjust the cutting edge of tool 109 merely by loosening bolt 131 slightly to permit the manual adjustment of tool 109 and adjusting plate 107 together about disc 108 and shoulder 105, respectively, and thereafter tightening bolt 131 to maintain the tool in its adjusted position.

While the invention has been described in connection with two specific embodiments thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come Within known or customary practice in the .art to which the invention pertains and as may be applied to the essential features hereinbefore set fonth, and as fall within the scope of the invention or the limits of the appended claims.

Having thus described our invention, what we claim is:

1. In a screw machine (a) a rotary Work spindle adapted to carry a workpiece,

(b) a slide reciprocable toward and from the work spindle,

(c) a tool oscillatably mounted on said slide,

(d) means for reciprocating said slide to move the tool toward and away from the work spindle into and out of engagement with the workpiece,

(e) spring-operated means mounted on said slide for rotating said tool,

(f) means operative on movement of said slide away from the work spindle to first cock said spring-operated means and then to latch said spring-operated means against operation, and

(g) means operative during movement of said slide toward said work spindle to disengage said latch means before the engagement of said tool with said workpiece, whereby said tool will be rotating under actuation of said spring-operated means before said tool engages the workpiece.

2. In a screw machine (a) a frame,

(b) a work spindle rotatable on the frame for holding a workpiece,

(c) a slide reciprocable on the frame toward and from the work spindle,

(d) a tool oscillatably mounted on said slide,

(e) means for reciprocating said slide to move the tool toward and from the work spindle into and out of engagement with the workpiece,

(f) a spring-actuated load-and-fire mechanism for rotating said tool,

(g) means operative during movement of said slide away from the work spindle to cock said load-andfire mechanism, and

(h) means operative during movement of said slide toward said work spindle and before engagement of said tool with the workpiece, to release said load-andfire mechanism thereby to rotate said tool before it engages the workpiece.

3. In ascrew machine (a) aframe,

(b) a work spindle journaled in the frame for holding a workpiece,

(c) a slide reciprocable on the frame toward and from the work spindle,

(d) a lettering tool oscillatably mounted on said slide and having an active working portion extending partway only around its periphery,

(e) means for reciprocating said slide to move the tool toward and from the work spindle into and out of engagement with the workpiece the active portion of said tool being disposed radially of the tool in position to be driven by engagement with the workpiece when the tool is engaged with the workpiece,

(f) a spring operated plunger reciprocable on said slide,

(g) means connecting the plunger to said tool to rotate the tool in opposite directions, respectively, on movement of the plunger in opposite directions respectively,

(h) means carried by the frame for cocking said plunger on movement of said slide away from the workpiece,

(i) latch means carried by said slide for releasably holding said plunger in cocked position, and

(j) means carried by the frame for releasing said latch means during movement of said slide toward the workpiece, whereby said tool is rotated before and as it engages the workpiece.

4. In a screw machine (a) aframe,

(b) a work spindle journaled in the frame for holding a workpiece,

(c) a slide reciprocable on the frame toward and from the Work spindle,

(d) a lettering tool oscillatably mounted on said slide and having an active portion extending part-way only around its periphery, said active portion being at a greater radial distance from the axis of said tool than the rest of the tool and said active portion being so disposed radially of the tool axis that the tool is rotatably driven by a rotating workpiece in said spindle when the tool is engaged with the workpiece.

(e) a second tool mounted on said slide and having a forming surface thereon,

(f) means for reciprocating said slide to move the tools toward and from the work spindle into and out of operative relation with the workpiece,

(g) a spring-actuated load-and-fire mechanism for rota-ting said first-named tool,

(h) means operative during movement of said slide away from the work spindle to cock said load-andfire mechanism, and

(i) means operative upon movement of said slide a predetermined distance toward said work spindle to release said load-and-fire mechanism thereby to rotate said first-named tool before it engages the workpiece,

(j) said slide reciprocating means holding said firstnamed tool in operative relation with the workpiece until the active portion thereof has rotated out of engagement with the workpiece, and being operative thereafter to advance the forming surface of the second tool into engagement with the workpiece before moving said slide away from said spindle.

5. In a screw machine (a) the forming surface on said second tool is at a greater radial distance from the common axis of said tools than the active portion of said first-named tool,

(b) said slide moving means is constructed to effect the movement of said slide toward the workpiece in two steps, one for moving the slide to bring said firstnamed tool into operative relation with the workpiece, and the other, after the active portion of said first-named tool has cleared the workpiece, to move the slide further radially toward the workpiece to cause the forming surface on said second tool to engage the workpiece.

6. In a screw machine having a frame, a rotary spindle for holding a workpiece, and a rotatable operating earn,

(a) a slide mounted on said frame for reciprocation toward and away from said spindle in response to the rotation of said operating cam,

(b) a roller carried by said slide to reciprocate therewith toward and away from a rotating workpiece mounted in the machine spindle, to an operative and an inoperative position, respectively,

(c) means mounting said roller on said slide for oscil- *lation between a first and a second position, respectively, relative to said slide,

(d) said roller having an embossed surface thereon which, when said roller is in its operative position, is engageable with the surface of the rotating workpiece during the movement of said roller from its first to its second position, thereby to engrave said embossed surface onto the surface of said workpiece,

(e) said mounting means including a spring constantly urging said roller toward its second position, and

(f) control means releasably holding said roller in its first position against the action of said spring and operative during the movement of said slide toward said spindle and prior to the engagement of said embossed surface with the surface of said workpiece to release said roller.

7. In a screw machine having a frame, a rotary spindle for holding a workpiece, and .a rotatable operating cam, (a) a slide mounted on said frame for reciprocation toward and away from said spindle in response to the rotation of said operating cam,

(b) a roller carried by said slide to reciprocate therewith toward and away from a rotating workpiece mounted in the machine spindle, to an operative and an inoperative position, respectively,

() means mounting said roller on said slide for oscillation between a first and a second position, respectively, relative to said slide,

(d) said roller having an embossed surface thereon which, when said roller is in its operative position, is engageable with the surface of the rotating workpiece during the movement of said roller from its first to its second position, thereby to engrave said embossed surface onto the surface of said workpiece,

(e) said mounting means including a spring constantly urging said roller toward its second position,

(f) control means releasably holding said roller in its first position against the action of said spring and operative during the movement of said slide toward said spindle to release said roller,

(g) a tool carried by said slide to reciprocate therewith and having a surface thereon adapted to engage and form the surface of the workpiece at a point spaced axially from that engaged by said roller,

(h) said slide being operative after the movement of said roller from its first to its second position, to advance further toward said spindle thereby to engage said tool with the rotating workpiece.

8. In a screw machine as defined in claim 11 wherein said control means comprises (a) a member connected to said roller for movement therewith relative to said slide, and

(b) a releasable latching element carried by said slide and engageable with said member to prevent movement of said member and said roller relative to the slide, when said roller is in its first position, and

(0) means on said frame engageable with said latching element, when said slide is moved toward said spindle, to move said element to a released position relative to said member.

9. In a screw machine having a frame, a rotary spindle for holding a workpiece, and a rotary operating cam,

(a) a slide reciprocably mounted on said frame,

(b) a roller mounted on said slide for rotation about an axis parallel to the axis of rotation of the spindle,

(0) means connecting said slide to said operating cam and operative upon rotation of said cam to reciprocate said slide and said roller toward and away from said spindle axis,

(d) said roller having thereon an arcuate, embossed surface adapted to rotate into engagement temporarily with the surface of a rotating workpiece mounted in said spindle thereby to engrave the embossed surface on said workpiece,

(e) means on said slide connected to said roller and operative, when said slide has moved said roller a predetermined distance toward said spindle axis, positively to rotate said roller in one direction to engage said stock, and operative, when said slide has moved said roller away from said spindle axis, to rotate said roller in the opposite direction, and the lastnamed means comprising (f) a member mounted on said slide for movement relative thereto between two limit positions,

(g) means interconnecting said roller and said member and operative upon movement of said member to one of said two limit positions to rotate said roller in said one direction, and to rotate said roller in said opposite direction upon movement of said member to the other of said limit positions,

(h) a spring constantly urging said member toward said one limit position,

(i) means on said frame operative to move said membet to said other limit position upon movement of said slide away from said spindle axis, and

(j) a latch engageable with said member upon movement of the latter to said other limit position to hold said member releasably in said other position against the action of said spring.

10. In .a screw machine as defined in claim 16 wherein (a) said latch is movably mounted on said slide, and

(b) a cam is secured to said frame to engage and move said latch to release said member, when said slide has moved said predetermined distance toward said spindle axis.

11. In a screw machine having a frame, a rotary spindle for holding a workpiece, and a rotary operating cam,

(a) a slide reciprocably mounted on said frame,

(b) a roller mounted on said slide for rotation about an axis parallel to the axis of rotation of the spindle,

(c) means connecting said slide to said operating cam and operative upon rotation of said cam to reciprocate said slide and said roller toward and away from said spindle axis,

(d) said roller having thereon an arcuate, embossed surface adapted to rotate into engagement tempo rarily with the surface of a rotating workpiece mounted in said spindle thereby to engrave the embossed surface on said workpiece,

(e) means on said slide connected to said roller and operative, when said slide has moved said roller a predetermined distance toward said spindle axis, positively to rotate said roller in one direction to engage said stock, and operative, when said slide has moved said roller away from said spindle axis, to rotate said roller in the opposite direction, and

(f) the movement of said slide toward said spindle axis being intermittent, and

(g) said operating cam effecting movement of said slide beyond said predetermined distance toward said spindle axis after each rotation of said roller in said one direction, and before each movement of said slide away from said spindle axis, and

(h) a tool having secured to said slide and has a surface thereon adapted to engage and form the surface of a rotating workpiece in said spindle upon the movement of said slide toward said spindle axis a distance greater than said predetermined distance.

12. In a screw machine having a reciprocable slide for moving a lettering roll into an operative and an inoperative position, respectively, relative to a rotating workpiece held in the machine spindle, a lettering roll holder comprising (a) a plurality of aligned plates secured to said slide,

(b) a rotatable shaft having a portion thereof mounted for rotation in an opening in one of said plates, and having a further portion extending into an aligned opening in another of said plates,

(c) a lettering roll secured to the first-named portion of said shaft to oscillate in a recess formed in said one plate between charged and discharged positions, respectively,

(d) a pinion secured to said further portion of said shaft to rotate in a further recess formed in said other plate,

(e) a segmental gear pivotally mounted in said further recess to mesh with said pinion,

(f) a plunger mounted for reciprocation between extreme positions in an opening in one of said plates other than said other plate,

(g) a pin connected at opposite ends thereof to said plunger and said segmental gear, respectively, and operative to pivot said segmental gear in response to the reciprocation of said plunger,

(h) a spring constantly urging said plunger toward one of its extreme positions, and

(i) a latch pivotally mounted on one of said plates and engageable with said plunger to hold it releasably 1 1 in the other of its extreme positions, said lettering roll being operative to oscillate in response to the reciprocation of said plunger. 13. In a screw machine as defined in claim 12, wherein (a) a forming tool is secured by said plates to said slide for movement therewith and has a cutting surface thereon which extends out from said plates at one end thereof to confront a rotating workpiece held in said spindle, and (b) said lettering roll has an embossed, arcuate surface thereon, which is disposed in said recess in said one plate when said roll is in either its charged or discharged position, and Which extends outwardly from said plates in the same direction as said tool during the oscillation of said roll.

References Cited by the Examiner UNITED STATES PATENTS Card 101-3 Scholtes 101-28 Douglass 101-7 Johnson 101-3 Norris et a1. 101-28 Friedman 101-7 X King 101-7 WILLIAM B. PENN, Primary Examiner. 

1. IN A SCREW MACHINE (A) A ROTARY WORK SPINDLE ADAPTED TO CARRY A WORKPIECE, (B) A SLIDE RECIPROCABLE TOWARD AND FROM THE WORK SPINDLE, (C) A TOOL OSCILLATABLE MOUNTED ON SIDE SLIDE, (D) MEANS FOR RECIPROCATIGN SAID TO MOVE THE TOOL TOWARD AND AWAY FORM THE WORK SPINDLE INTO AND OUT OF ENGAGEMENT WITH WORKPIECE, (E) SPRING-OPERATED MEANS MOUNTED ON SAID SLIDE FOR ROTATING SAID TOOL, (F) MEANS OPERATIVE ON MOVEMENT OF SAID SLIDE AWAY FROM THE WORK SPINDLE TO FIRST COCK SAID SPRING-OP ERATED MESNS AND THEN TO LATCH SAID SPRING-OPERATED MEANS AGAINST OPERATION, AND (G) MEANS OPERATIVE DURING MOVEMENT OF SAID SLIDE TOWARD SAID WORK SPINDLE TO DISENGAGE SAID LATCH MEANS BEFORE THE ENGAGEMENT OF SAOD TOOL WITH SAID WORKPIECE, WHEREBY SAID TOOL WILL BE ROTATING UNDER ACTUATION OF SAID SPRING-OPERATED MEANS BEFORE SAID TOOL ENGAGES THE WORKPIECE. 